As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
JUST PRIOR TO DESCENT LEFT SIDE WINDOW OVERHEAT LIGHT ILLUMINATED. TURNED SWITCH TO OFF FOR FOUR MINUTES TURNED BACK ON AND OVERHEAT LIGHT ILLUMINATED AGAIN. CHECKED CIRCUIT BREAKERS AND FOUND LEFT SIDE BREAKER HAD POPPED. FOUND C/B B8 ON P6 12 OPEN. RESET PER MM 20 60 01 860 801. LEFT SIDE WINDOW HEAT OPS NORMAL REF MM 30 41 710 801. ETOPS GND VERIFICATION TEST SUCCESSFUL.